1. Field of the Invention
The present invention relates to a linear guide used in e.g., an industrial machine field and an under seal attached to the linear guide.
2. Description of the Related Art
FIG. 16 shows a linear guide of a related art.
This linear guide has a guide rail 1 extending in an axial direction and a slider 2 laid across the guide rail 1 so as to relatively move on the guide rail 1 in the axial direction.
A rolling element rolling groove 3 extending in the axial direction is formed on each of both side faces of the guide rail 1. A rolling element rolling groove 7 opposed to the rolling element rolling groove 3 is formed on each of the inside faces of both sleeve portions 4 of a slider main body 2A of the slider 2. Many balls B as one example of a rolling element are rotatably mounted between both these rolling element rolling grooves 3 and 7 facing each other. The slider 2 can be relatively moved along the axial direction on the guide rail 1 through the rolling movements of these balls B.
As this movement is made, the ball B interposing between the guide rail 1 and the slider 2 rolls and moves to an end portion of the slider 2. However, it is necessary to infinitely circulate these balls B so as to continuously move the slider 2 in the axial direction.
Therefore, a rolling element passage 8 extending through the interior of the sleeve portion 4 of the slider main body 2A in the axial direction is formed. For example, an end cap 5 approximately formed in a U-shape is fixed to each of both ends of the slider main body 2A through a fixing means such as a screw 12, etc. A direction changing passage 6 curved in a semi-arc shape and communicating the rolling element passage 8 and a portion between both the above rolling element rolling grooves 3 and 7 is formed in this end cap 5. Thus, a rolling element infinite circulation orbiting path is formed. In FIG. 16, reference numeral 11 designates a side seal fixed to an end face of the slider main body 2A through a screw 12, etc. together with the end cap 5. Reference numeral 10 designates a tap hole of the screw 12 formed on the end face of the slider main body 2A. Reference numerals 13 and 14 respectively designate a nipple for grease supply, and a bolt insertion hole for fixing the guide rail 1.
An unillustrated inner seal and an under seal 15 are used as a member for sealing the portion between the slider 2 and the guide rail 1 in addition to the above side seal 11. The inner seal is arranged in a position opposed to both sides of the upper face of the guide rail 1 of the slider main body 2A. As shown in FIGS. 17 and 18, etc., the under seal 15 is arranged along the axial direction on an under surface of the slider main body 2A and comes in slide contact with the side face of the guide rail 1, and seals the under surface of the slider main body 2A.
The under seal 15 has a core bar 16 of a long plate shape long in the axial direction of the slider main body 2A, and a rubber seal 17 fixedly attached to this core bar 16. The under seal 15 is held by inserting its both end portions into holding grooves 19 (see FIG. 17) arranged in the end cap 5 in a state in which the under seal 15 is arranged on the under surface (see FIGS. 18 and 19) of the slider main body 2A, or is arranged in a storing concave portion 18 (see FIGS. 20 and 21) concavely arranged on the under surface. A sliding lip portion 20 formed at a width direction inside edge of the under seal 15 comes in slide contact with the side face of the guide rail 1 so that the under seal 15 seals the under surface of the slider main body 2A.
However, in the above related linear guide, the under seal 15 is held only by the holding groove 19 of the end cap 5. Therefore, the close attaching property to the slider main body 2A is weak and a gap is easily generated between the slider main body 2A and the under seal 15, and foreign matters, etc. easily enter from the gap.
Further, when the under seal 15 is arranged in the storing concave portion 18 (see FIGS. 20 and 21) concavely arranged on the under surface of the slider main body 2A, foreign matters, etc. are easily collected in a concave portion 21 formed between the under seal 15 and the under surface of the slider main body 2A.
The under seal 15 is directly fixed to the under surface of the slider main body 2A by a rivet 22 as a means for solving the above problems (see FIG. 22). However, when the under seal 15 is once fixed to the under surface of the slider main body 2A by the rivet 22, no under seal 15 can be easily detached. Further, it is necessary to process a hole of the rivet 22 in the slider main body 2A so that cost is increased. Furthermore, a problem exists in that it takes time and labor such as a rivet striking work at an assembling time of the under seal 15 and a rivet removing work, etc. at an exchanging time of the under seal 15.
Further, when the rivet 22 is strongly struck, the under seal 15 is excessively crushed by the rivet 22 so that the end portion and the intermediate portion of the under seal 15 are deformed in a wavy shape and a gap is easily generated between the under seal 15 and the slider main body 2A. Furthermore, an additional attachment space is required since the head of the rivet 22 is projected to the under surface of the slider main body 2A.